High speed tube mill

ABSTRACT

Apparatus for rocking the work rollers and turning and feeding the blank of a pilger mill to provide a mill which will operate at very high speeds and produce accurately dimensioned thin walled tubes even of refactory type metals.

United States Patent [191 Sporck Aug. 21, 1973 [54] HIGH SPEED TUBE MILL 2,161,065 6/1939 Krause 72/209 1,952,841 3/1934 Coe 72/214 [75] Traverse 2,594,126 4/1952 Coe 72/208 Mlch- 3,030,835 4/1962 Krause 72/209 [73] Assignee: Hitco Ga'rdena, Calif: 3,411,336 11/1968 Wadleck 72/209 [229] Filed: 1970 Primary Examiner-Richard .1. Herbst [2]] Appl. No.: 66,342 Att0rneyFrederick .1. Olsson [52] US. Cl. 72/214, 72/250 [57] ABSTRACT [51] Int. Cl B211) 21/06 581 Field of Search 72/214, 209, 189, AWrams fmfmkmgthe mum and and 72/250 feeding the blank of a pilger mill to provide a mill 2 which will operate at very high speeds and produce ac- [56] References Cited curately dimensioned thin walled tubes even of refac- UNITED STATES PATENTS type metals 822,879 6/1906 Briede 72/189 6 Claims, 16 Drawing Figures 3e 45 I a 4 22 \J 25 \IO In g l PAIENIEU 1 SHEEI 1 OF 7 INVENTOR.

CLAUS L. SPORCK ATTORNEY.

Pmmmm" 3.753.370

SHEU 2 0F 7 INVENTOR. AUS L; SPORCK Frederick J. Olsson ATTORNEY.

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PAIENIEU m2 I ma SHEET 3 BF 7 INVENTOR. CLAUS L. SPORCK Frederick J. Olsson ATTORNEY.

sson

Frederick J. OI

ATTORNE I 9 A L SHEET 5 BF 7 w l; R W QQ ti manna M W PAIENIEB 1 3. 7 58 370 sum? or 7 NVEN CL L. SP CK l5l Frederick J. Olsson ATTORNEY- 1 HIGH SPEED TUBE MILL This invention relates to an improved tube mill for producing tubes particularly small diameter, thin wall tubes.

The principal object of the invention is to provide pilger or tube mill apparatus which operates to rock the work rollers at very high frequency, at very short stroke and to feed the blank at very small increments whereby only an extremely small quantum of metal is worked in any one pass of the rollers.

Advantageously a mill characterized by a structure developing the operating characteristics as aforesaid provides for high area reduction, extrudes finished tubes at rates much higher than conventional mills, greatly lowers the percentage variation in diameter, wall thickness and concentricity over conventional tubes and provides for rapid production of small diameter, thin walled tubes from alloys of metals such as titanium and zirconium, for example, tubes of one-half inch diameter and 0.003 walls.

In addition to the capabilities of high speed and miniaturization of tube size in a wide spectrum of metals, the invention has other important and practical advantages. For example, the invention provides for reduction in the power requirements or the force necessary to work the blank, provides a significant reduction in the size of the components making up the mill and has the ability to hot roll or maintain the blank at an elevated temperature by the rocking action of the rollers.

A preferred form of the invention will be described below in connection with the following drawings wherein:

FIG. I is a side elevational view of a tube mill incorporating the invention.

FIG. 2 is a plan view of FIG. 1.

F IG. 3 is a side elevational view taken along the lines 3-3 of FIG. 2 and illustrating the blank feeding and turning mechanism.

FIG. 4 is a front elevational view of the feeding and turning mechanism as taken along the lines 4-4 of FIG. 1.

FIG. 5 is an elevational view taken long the lines 5-5 of FIG. 4.

FIG. 6 is a side elevational view taken along the lines 6-6 of FIG. 2 and illustrating the roller rocking mech anism.

FIG. 7 is an elevational view taken along the lines 7-7 of FIG. 6.

FIG. 8 is an elevational 8-8 of FIG. 6.

FIG. 9 is an elevational view taken along thd lines 9-9 of FIG. 8; and

FIG. 10 is a diagrammatic illustration of certain of the components of FIG. 9.

FIG. 1 l is a sectional plan view taken along the lines 11-11 of FIG. 9.

FIG. 12 is a sectional view taken along the lines l2-l2 in FIG. 6.

FIG. 13 is a view taken along the lines 13-13 of FIG. 12.

FIG. 14 is a fragmentary view of a preferred form of roller construction.

FIG. 15 is a view looking toward the left in FIG. 14; and

FIG. 16 is a view is another embodiment of a preferred roller construction on a reduced scale.

view taken along the lines It will be understood that the term pilger mill" as used herein is inclusive of the reciprocating two roller type of mill and also the type of mill having more than two rollers, for example, three reciprocating rollers spaced apart around the axis of the tube.

In FIGS. 1 and 2 a generally elongated bed for the mill is indicated at l. The left hand side of the bed carries the tube reducing or rocker mechanism 2. The blank feeding and turning mechanism 3 on the right hand side is adapted to be moved along the bed up to the rocker 2 and then back to position as shown.

The work rollers supported within the rocker mechanism 2 are indicated in FIG. 6 by R-1 and R-2. Each roller has a circumferential tapering and laterally flaring working groove such as the grooves g-l and g-2. The grooves are opposed and form a mouth which is concentric with respect to the axis A and within which tubular blank is to be worked. The inside of the blank is supported by a mandrel. When the rollers move for the working stroke the grooves g-l and 3-2 engage and roll or rock over the blank. The gradually decreasing size of the mouth reduces the wall of the blank and works the blank down on the mandrel.

For the return stroke the rollers rock or roll back over the blank in the opposite direction and are essentially disengaged from the blank so that the same can be fed forward and turned.

The blank to be worked extends along the axis A and on the right hand side the blank is supported by the feed and turn mechanism 3 and the left hand end is sup ported by the mandrel in the mouth of the work rollers as aforesaid. Between roller strokes, the feeding and turning mechanism 3 incrementally feeds the blank to the left along the axis A and turns the blank around the axis A. The finished tube extrudes out of the left hand end of the rocker assembly.

The mandrel is mounted on a mandrel rod which extends from left to right within the tube along the axis A through the feeding and turning mechanism 3 and hence to the chuck 4. For the sake of clarity the tube, mandrel and mandrel rod are not shown.

The invention contemplates that the blank alone be fed forward and turned between roller strokes and thus the mandrel is held against both turning and axial movement by the chuck 4. However, as will be more apparent hereinafter the invention contemplates the mandrel and tube to turn in unison.

To achieve the purposes as stated above, the invention contemplates roller speeds to 750 strokes per minute for tubes of 1 inch diameter and as high as 2,500 strokes per minute for tubes of half inch diameter. Inasmuch as the blank must be turned and fed after each working stroke the feeding and turning mechanism must be instant starting.

To achieve instant starting, the invention contemplates imposing a torque and an axial thrust on the blank during the working stroke so as the rollers release the blank on the return stroke the turning and feeding forces immediately come into play for the turning and feeding operations. The magnitude of torque and thrust is adequate for turning and feeding. The amount of turn and feed is controlled by that the rollers firmly grip and engage the blank at the end of the return stroke. As will be described shortly, however, the invention contemplates a separate mechanical arrangement for controlling the amount of blank feed.

It will be appreciated that with the rollers reciprocating at very high rates of speed the time for a return stroke is only a fraction of a second. Thus, the time within which the blank can feed forward and turn before being gripped is very small. By way of example, the amount of forward feed may be in the order of 0.003 inches to 0.090 inch per stroke and the amount of turn a fraction of a degree. Feeding and turning apparatus to meet the foregoing will be described in connection with FIGS. 2, 3, 4 and 5.

As indicated at FIG. 2 a pair of guide rods 5 and 6 extend along the axis of the bed. The guide rods are supported at their opposite ends and also at several places between the ends. For example with reference to FIG. 5 it will be seen that the guide rod 5 is supported on its right hand end by the block 10. A similar block 11 supports the left hand end (FIG. 2). A plurality of intermediate blocks such as the block 12 in FIG. 5 support the rod between the ends.

Between the guide rods is a feed screw 13 which is rotatably mounted on the bed by the bearings 14 and 15. A coupler l6 joins the right hand end of the feed screw to a drive shaft 20, the right hand of which is rotatably supported by the bearings 21. The drive shaft 20 is connected to a sheave 22 driven by the belt 23 connected to the speed control motor 24.

A generally rectangular, horizontally oriented platform 25 is connected to the feed screw 13 as by the nut 26. The platform 25 is slidably supported on the guide rods 4 and 5 by pairs of bushings, for example, in FIG. 5 the bushings 30 and 31 mounting the platform on the guide rod 5.

Rotation of the feed screw 13 causes the platform 25 to move along the guide rods toward the rocker 2 and rotation of the screw in the opposite direction brings the platform back to the position as shown.

The platform 25 fixedly mounts four posts 32 which extend upwardly and in turn support the platform 33. The platform 33 carries a speed control motor 34.

A drive spindle 35 is rotatably mounted on the platform 25 as by the bearings 36. The spindle carries a sheave 40 having a belt driving connection 41 to the motor 34. The speed of the motor 34 is controlled whereby to control the rotational speed of the drive spindle 35.

The drive spindle is hollow and mounts a chuck spindle 42 carrying the tube chuck 43. The chuck spindle 42 makes a splined connection 44 with the drive spindle 35. The splined connection provides for relative axial motion as between the spindles in a direction along the tube axis A. The'chuck 43 is of conventional construction and when its jaws are turned down a tube extending along the axis A can be firmly gripped so as to rotate with the chuck. As noted, both the chuck 43 and the chuck spindle 42 are hollow and this construction provides for the mandrel rod and a tubular blank to extend therethrough.

From the foregoing description it will be apparent that the motor 34 can impose a turning torque on a chuck 43 and hence a turning torque on a blank gripped thereby. When a blank is gripped during the working stroke operation of the motor will impose a turning torque on the blank. The torque acts in a direction around the axis A. The amount of torque need only be great enough to turn the blank when it is free from the rollers. However, it will be understood that when the blank is gripped by the rollers any necessary compensation for the turning torque will be provided by the tendency of the blank to twist. Furthermore, with the high rate of roller reciprocation the time within which a blank is gripped is only a matter of a fraction of a second so that any actual physical twist of the blank is negligible. I

Also, it will be apparent to those skilled in the art, the time over which twisting torquecan be developed on the blank during the working stroke can be reduced by incorporating a lost motion arrangement such as a rotary air or mechanical spring in the drive between the motor 34 and tube chuck 43.

Thus, it is contemplated to run the motor 34 constantly so as to impose the torque on the chuck 43 during the time the rollers are in the working stroke and during the time the rollers are in the return stroke. The turning torque is operative for turning the blank instantaneously or simultaneously with the release of the blank by the rollers on the return stroke. The blank, of course, is turned during the return stroke and presents to the rollers another section of the blank to be worked on the next working stroke. When the rollers have finished the return stroke and have again tightly engaged the blank the turning is terminated and the torque immediately begins to build up for release at the end of the next working stroke.

The motion of the platform 25 toward the rocker assembly 2 imposes the necessary axial thrust on the blank for the instant feeding condition. This is explained following.

A hollow cylinder 45 is fixedly connected to the platform 25. The cylinder mounts a hollow piston 46. The bearing means 47 connect the piston with the chuck spindle 42 and provides for rotary motion of the chuck spindle with respect to the piston and for the piston and chuck spindle to move axially in unison.

The piston 46 is shouldered so as to form the fluid v pressure chamber 50. The chamber is connected to the fluid pressure supply means not shown. The fluid pressure in chamber 50 exerts pressure or an axial thrust to move the piston 46, hence the chuck spindle 42 and chuck 43 toward the left or toward the rocker assembly 2. The outboard end of the piston 45 carries the thread 51 and on which is mounted the stop nut 52. Ordinarily the stop nut 52 is backed off so that the fluid in the chamber 50 forces the piston toward the left and the stop nut 52 moves up against the cylinder 45. It will be seen therefore that the position of the stop nut on the threads 51 determine the amount of movement of the chuck 43 in the left hand direction or toward the rocker assembly.

The manner in which the foregoing operates to impose the axial thrust will next be described.

Assume that the nut 52 has been backed off, that the pressure in chamber 50 has forced the piston 46 (and chuck 43) toward the left to increase the axial size of the chamber 50 and that with the foregoing condition, the blank has just been gripped by the rollers at the end of the return stroke. When the blank is gripped, axial motion of the chuck and the blank toward the left is prevented. The motor 24 constantly rotates so the feed screw 13 operates during the working stroke to move the platform 25 and cylinder 45 to the left towards the rocker assembly 2. Motion of the platform 25 and the cylinder 45 towards the rocker assembly is accommodated by the fact that the cylinder 45 moves toward the left toward the piston 46 and in doing so contracts the axial size of chamber 50. The fluid in the chamber is compressed and this exerts an axial thrust on the piston 46 which is transmitted through the bearings 47, the chuck spindle 42 and chuck 43 to the blank. It will be understood therefore that immediately upon the release of the blank by the rollers, the force in the chamber 50 shoots the chuck and blank forward.

The axial size of chamber 50 increases so as to accommodate cylinder 45 motion on the next working stroke. The amount of forward motion or feed is determined either by the position of the nut 52 or by the rollers firmly engaging the blank at the end of the return stroke.

Therefore, it will be seen that the blank has imposed on it an axial thrust during the time the rollers are in the working stroke and during the time the rollers are in the return stroke so that this feeding thrust is operative and available for feeding the blank instantly or simultaneously with the release of the blank by the rollers. The blank is fed during the return stroke and presents to the rollers a small section of blank to be worked for the next working stroke. The effect of the thrust during the working stroke as explained above is accommodated by the sliding connection between the cylinder 45 and piston 46 and the turning of the blank is accommodated by the bearings 47.

The mandrel chuck 4 is of conventional construction and is fixed on the bed 1 by the standard mechanism 49. It will be observed that the piston 46, the chuck 4 and the standard 49 are all hollow so as to accommodate a mandrel rod and/or a blank to be inserted therethrough.

The rocker assembly 2 mounting the rollers R-1 and R2 for short stroke, high frequency reciprocation or rocking will next be described.

In general the rocker assembly includes a box-like frame 53 (FIG. 1), a roller saddle 54 (FIG. 6) together with the saddle drive mechanism 55.

The frame 53 comprises the bottom plate 56 secured on the top of the bed, two spaced apart side plates 60 and 61 which are fixed to the bottom plate, the top plate 62 together with an end plate 63 connected to the base and to the side plates.

The bottom plate 56 carries a V-shaped guideway 64 and the top plate 62 carries an identical V-shaped guideway 65. The ways are symmetrically disposed with respect to the axis A. The guideways 64 and 65 mount the saddle 54 for reciprocating motion on the frame in a direction along the axis A. The saddle structure will now be described.

The saddle 54 includes a pair of spaced apart rectangular shaped side plates and 71 which are oriented generally parallel each other and are symmetrically disposed with respect to the axis A on opposite sides of the plane P.

On the left hand side, (FIG. 6) the plates 70 and 71 are shouldered as indicated at 72 and 73. On the opposite side the plates are shouldered as indicated at 74 and 75. The shoulders 72 and 73 respectively carry end brackets 80 and 81 which extend between and are fixedly connected to the saddle side plates 70 and 71 as shown in FIG. 7. The shoulders 74 and carry similar end brackets 82 and 83. The end brackets function as structural members interconnecting the side plates 70 and 71 and in addition carry guide rollers which move upon the guideways 64 and 65. Thus, the end bracket carries the guide rollers 84 and 85 which mate with the guideway 65. The other end brackets carry identical guide rollers.

The saddle 54 is adapted to reciprocate on the frame by the drive mechanism 55 which in essence is a servo controlled double acting piston which can reciprocate at very high frequency at a very short stroke.

The cyclinder is fixedly mounted on the frame end plate 63. The cylinder carries a drive piston indicated at 91 which is mounted in the cylinder for reciprocating motion in a direction along the axis A. The motion of the cylinder is caused and controlled by fluid pressure change in the cylinder. The servo control mechanism 92 causes the desired pressure changes. The piston 91 has a double ended piston rod, one end of which is indicated at 93 and the other at 94. Both the piston 91 and the piston rod 93 and 94 are hollow as indicated by the dotted line 95 to accommodate passage of a finished tube along the axis A. The piston rod 94 carries a bracket 96 which in turn is connected into an arm 97 slidably mounted in the frame side wall 60. The arm is connected to a linear transducer which senses the actual position of the piston 91 and sends an electrical signal to the control 92, this information being utilized by the servo to control the piston operation. The cylinder 90, piston 91 and control 92 are of conventional construction and need not be described further.

The manner in which the drive 55 is coupled up to the saddle 54 is an important part of the invention particularly with respect to the high rate of saddle reciprocation. The coupling means automatically compensates for any misalignment of the saddle and drive piston and cylinder with respect to the tube axis A. The coupling means will next be described.

A saddle ring 100 is fixed to the saddle side plates 70 and 71. The saddle ring is apertured as indicated so as to accommodate the passage of a finished tube. A lock ring 101 is fixed to the saddle ring. As best indicated in FIG. 7 the saddle ring and the lock ring are interconnected to each other and to the saddle side plates 70 and 71 as by the bolts 102. A piston ring 103 is threadingly engaged with the piston rod 93. The piston ring is apertured to accommodate passage of a finished tube therethrough. The piston ring 103 is locked on the piston rod by conventional means such as set screws.

The saddle ring is formed with an annular socket 104 and the piston ring is formed with a head 105 which extends into the socket. The inside diameter of the socket is greater than the outside diameter of the head. This difference in dimension will accommodate relative motion between these components in a direction radially of the axis A. Therefore, any radial misalignment between the saddle and the saddle drive will be taken care of by the fact that these components can seek their own relative radial positions without imposing stresses on one another.

For the driving function, it is important that the piston ring and the saddle ring be held rigidly together particularly in a direction along the axis A. For this purpose I provided a fluid pressure means in the form of a flat surface 106 on the saddle ring and a flat surface 107 on the piston ring together with a pair of O-rings 110 and 111 concentrically disposed on the surface 107. The O-rings and the flat surfaces form an annular fluid pressure chamber which is adapted to be supplied through the connection indiciated at 112. It will be apparent that when fluid is introduced into the chamber the saddle ring and piston rings will tend to move relatively apart and this will force the head 105 on the piston ring firm against the lock ring 101 to establish the condition for reciprocating drive. When the mill is not in the saddle driving condition, the pressure in the chamber is reduced so as not to interfere with the misalignment adjustment as described above.

One of the most important features of the invention is the mechanism permitting the roller to rock or be reciprocated at very high rates. For this purpose the invention contemplates a power driven saddle which moves the roller in translation together with stop means constantly imposing a restraint to the roller's translatory motion at a point spaced from the rotational axis. This causes the roller to turn while moving in translation and hence rock or roll over the blank. The drive and the constantly applied restraint allows extremely high reciprocating action as they provide that there are no parts to collide with one another (such as with gears) with the consequent elimination of collision damage. A preferred form of the mechanism will be described following.

Referring to FIG. 8 the roll R-1 is fixedly connected to a shaft 112 and the roller R-2 is fixedly connected to the shaft 1 13. The bearings 1 14 rotatably mount the shaft 112 in the saddle side plates 70 and 71. The shaft 118 is rotatably mounted in the saddle side plates 70 and 71 by the bearings 115. The opposite ends of the shafts extend outwardly into the cut-outs 116 and 117 in the frame side walls 60 and 61.

Fixedly connected to the outer ends of the shaft 112 are the rock arms 120 and 121. The arms extend downwardly from the rotational axis of the shaft 112 (or roller R-l) in a direction toward the rotational axis of the shaft 113. The outer ends of the shaft 113 carry the rock arms 122 and 123 which are fixedly secured to the shaft and extend radially upwardly from the rotational axis of the shaft (or roller R-2) in a direction toward the rotational axis of the shaft 112.

As best shown in FIGS. 9 and 10, the outer extremities are generally circular as indicated by the extremity 1220 of the rock arm 122.

The circular outer extremity of each arm is engaged with stop means which are arranged to control the motion of the arm as the saddle reciprocates in the work stroke and in the return stroke. This arrangement will be explained in connection with the arms 120 and 122.

Referring to FIG. 11, the frame side plate 61 mounts a carrier 124. The carrier mounts the shafts 125 and 126 on which are rotatably mounted stop bearings 130 and 131 inter-engaged with the extremity 120a of the arm 120.

As shown, the bearings 130 and 131 engage 122a and the bearings 132 and 133 engage 120a in a plane P-l which contains the axis of the blank. The arm 120 and stop bearing rollers 132 and 133 are similarly arranged. Also, the arms 121 and 123 on the opposite sides of the saddle are engaged with identical stop bearings with the engagement taking place in the plane P-1.

Inasmuch as the roller shafts 112 and 113 are mounted directly on the saddle, the shafts, the rollers and the interconnected rock arms will partake of the same reciprocating motion as the saddle. As the saddle moves in translation, the rotation axes of the rollers (or shafts) also move in translatory action. The motion is parallel to the tube axis A. For example with reference to F 1G. the shaft moves along the axis A-l while the shaft 113 moves along A-2.

With reference to FIGS. 6, 9 and 10 the saddle moves to the left for the working stroke and moves to the right for the return stroke. As shown, the rollers are in the mid position. The total movement of the saddle for the working and return strokes is controlled by the drive mechanism 55 and is a function of whether all or part of the working grooves are to roll over the blank. The mouth formed by the working grooves will be widest at the beginning of the working stroke (end of return stroke) and narrowest at the end of the working stroke (start of return stroke).

When the saddle is moving in translation during the working and during the return stroke, the roller shafts 1 12 and 113, the rollers and the rock arms all will tend to partake of this translatory motion. Now then, with reference to FIG. 10, it will be apparent that when the saddle is moving to the left in the working stroke, the translatory motion of the rollers will be resisted by virtue of the fact that the rock arms and 122 are engaged with the stop bearings and 132. The contact with the stop bearings causes the rollers to turn while moving in translation and therefore roll or rock over the tubular blank to work the same.

When the saddle is moving tothe right in the return stroke the translatory motion of the rollers will be resisted by virtue of the rock arms being in contact with the stop bearings 131 and 133. This will cause the rollers to turn while moving in translation and hence rock over the blank. In the return stroke the rollers are out of working or reducing contact with the blank except for possible flashing due to the split nature of the rollers.

The dotted lines 134 and 135 diagrammatically illustrate the position of the rock arms at the end of the return stroke and the lines 136 and 137 the position at the end of the working stroke.

It is critically important to the proper functioning of the above to constantly maintain the restraint during the time the rollers are moving and at the time theyare shifting from one stroke to the other. In other words, in the embodiment described, the rock arms are constantly maintained in contact with the stop bearings. For such purposes the shafts 125 and 126 mounting the bearings are eccentric to provide the proper adjustment for maintaining the contact.

It will be apparent as the rollers move say from the mid position shown in FIG. 10 to either extreme position, the rock arms will move slightly upwardly and slightly out of the contact plane P1. Thus, when the rollers are moving from the mid position to the end of the return stroke the rock arm 120 will tend to move clockwise with respect to the axis of the bearing 133 and counterclockwise with respect to bearings 132. The rock arm 122 will tend to move counterclockwise with respect to the axis of the bearing 131 and counterclockwise with respect to bearing 130. Since the bearings are rotatable, the foregoing motion of the arms will rotate the bearings and therefore minimize or eliminate any sliding of the arm.

Depending upon the size of the components and the maximum roller stroke it will be understood that the outer extremities of the rock arms may take a shape or contour other than circular in order to further minimize the tendency for any sliding action as between the arms and the stop bearings.

Before going on it is pointed out the stop bearings on the frame and portions of the rock arms in contact 9 therewith respectively constitute stop means which are engaged with one another.

With respect to the rocking action as described above, it will be observed that the contacts between the rock arms and the stop bearings is maintained essentially within the plane P-l. This provides a l-l ratio as between the saddle motion and rocking of the rollers. The ratio, of course, can be changed by moving the contact point closer to or farther from the rotational axis of the roller.

Preferably, the rollers are made up with interchangable inserts which are provided with the working grooves. This adapts the mill for various kinds and sizes of tubes. In FIGS. 12 and 13 l have shown the preferred manner for locking the inserts in the roller. For example, in FIG. 12 the roller R-l has a cavity 140 in which is disposed the insert 141. The working groove of the insert is indicated at g-l. The roller has a pair of radial bores 143 and 144 in which are disposed the insert holders 145 and 146. Each holder has a tapered surface such as the surface l50.for the holder 145 which mates with a corresponding tapered surface such as the surface 151 on the insert. By manipulating the screws 152 the inserts can be pulled up on the bores and hence to firmly lock the insert in the cavity.

With the high frequency, short stroke and small blank feed, the amount of metal which is rolled down during any one working stroke is very small, for example, volume in the order of fractional cubic inches and depending upon the type of metal, the force required tomove such a quantum metal will be very small. Thus, the power requirements for working tubes of various sizes and various types of metals isconsiderably reduced and consequently the components of the mill commensurately smaller.

With the type of operation as above described, it is contemplated that under certain conditions the rolling may be done hot rather than cold by virtue of the heat generated in the working operation being utilized to elevate and maintain temperature of the inserts whereby the temperature of the blank within the stroke area of the rollers is maintained at an elevated temperature. For this purpose it is contemplated that the inserts be of tungsten carbide.

The working grooves 3-1 and g-2 of the rollers may take the conventional form in having a reducing section which is longitudinally tapering and laterally flaring and a smoothing or ironing section which is essentially cylindrical. The details of such construction is not shown as the same is well known in the art.

The invention, however, contemplates a roller groove structure which is particularly adaptable for the high speed operation as described herein in that it enhances the gripping and rolling action, has a stabilizing effect on the blank both longitudinally and circumferentially and enhances tube concentricity and dimensional accuracy.

Such roller structure is shown in FIGS. 14, and 16 where the rollers 150 and 151 have respectively reducing grooves 152 and 153 and finishing grooves 154 and 155. The starting end for each reducing groove is indicated at 156 and 157 and the finishing end at 160 and 161. Each reducing groove is circumferentially tapered by that it is eccentric with respect to the roller rotational axis. The groove is laterally flaring by that it is wide at the starting end and narrow at the finishing end.

On each of the reducing grooves there are a plurality of stabilizing grooves. The stabilizing grooves on the reducing grooves 152 are indicated at 162 and the stabilizing grooves for the reducing at 153 indicated at 163. The stabilizing grooves extend from the starting end to the finishing end and each groove is circumferentially tapering and laterally flaring in the same direction as its reducing groove. By way of example, a stabilizing groove at the starting end'may be circular with a diameter in the order of a few thousand with zero dimensions at the finishing end. Preferably, the total number of stabilizing grooves around the roller mouth is an odd number in order to enhance the compatability of the stabilizing grooves with the turning of the blank.

In FIG. 16 l have shown an embodiment wherein the stabilizing grooves are set up side by side. The rollers 164 and 165 have reducing grooves 166 and 167. Stabilizing grooves 170 and 171 are formed on the reducing grooves. The shape of the grooves make a sinusoidal pattern around the mouth of the opening of the rollers. As in FIG. 15 there are an odd number of these grooves. It will be observed that each groove 170 and 171 has length and breadth dimension at the starting end of the reducing groove which fades away to zero dimensions at the finishing end.

While I have shown the stabilizing grooves of FIG. 16 to all be of the same dimension the invention contemplates that the grooves be of different dimensions, for

example, that the grooves be alternatively shallower and deeper.

One of the important advantages of the stabilizing grooves is in the function of converting the rough, high tolerance blank into a finished tuhe having a wall which is substantially uniform in wall thickness and in diameter all along the axis of the tube. Thus, during a working stroke on a blank which is eccentric, the excess metal on the thicker side will occupy the space provided by the stabilizing grooves rather than be forced ahead. The thicker side can be taken down more gradually so that less force is required for a one roller pass.

In cases where it is desired to synchronously turn the tube and the mandrel, the invention contemplates mod ifying the apparatus described following.

The mandrel chuck 4 is rotatably mounted in bearings in the standard 49. The chuck 4 then is arranged to be driven in a l1 ratio with the tube chuck 43. For this purpose a splined rod is rotatably mounted in the bed. On the rod is a drive sheave connected with the platform 25 so as to be movable with the platform along the splined rod. The drive sheave is connected by belt to a sheave on the drive spindle 35. Rotation of the spindle 35 imports rotation to the splined rod. The aft end of the splined rod has a sheave-belt connection up to the tube chuck 4. Thus, it will be apparent that each time the motor 34 operates to turn the tube chuck, the mandrel chuck will also be turned.

I claim:

1. In a high speed tube mill:

roller means adapted to reciprocate back and forth to work a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller rolling back over the worked blank while releasing the same for turning and moving axially;

a chuck to grip a blank to be worked; means supporting the chuck to turn and feed the blank after each working stroke including:

a. mechanism to impose torque on the chuck during the time the rollers are in the working stroke and during the time the rollers are in the return stroke whereby the turning torque is operative for turning the blank simultaneously with the release of the blank by the rollers on the return stroke and the blank is turned during the return stroke for presenting to the rollers a section of the blank to be worked on the next working stroke, the effect of the torque on the blank during the working stroke being accommodated by twist of the blank;

b. mechanism to impose an axial thrust on the chuck during the time the rollers are in the working stroke and during the time the rollers are in the return stroke whereby the axial thrust is operative for feeding the blank simultaneously with the release of the blank by the rollers on the return stroke and the blank is fed axially during the return stroke toward the rollers for presenting to the rollers a section of blank to be worked on the next working stroke, the effect of the thrust during the working stroke being accommodated by that the mechanism has a sliding connection and the turning of the blank being accommodated by that the mechanism has a rotary connection; and

means to determine the amount of turning and axial feed of the blank.

2; Blank feeding and turning apparatus for a high I speed tube mill comprising:

an elongated bed;

a pair of spaced apart horizontally extending guide rods fixed on the top of the bed;

a horizotally extending feed screw rotatably mounted on the bed between said guide rods;

means connected with the bed to rotate the feed screw;

a first horizontally extending platform;

bushing means slidably mounting the platform on the guide rods for movement along the bed;

a nut on the feed screw and connected with the platform, rotation of the screw in the nut moving the first platform along the bed;

a second platform disposed above the first platform and moveable therewith;

a drive motor mounted on the second platform;

a hollow drive spindle rotatably mounted on the first platform;

a drive connection between the drive spindle and the drive motor for rotating the spindle;

a hollow chuck spindle;

means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison; 1

a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for the turning and feeding of the blank;

a cylinder mounted on the first platform;

a hollow piston mounted for reciprocating motion within the cylinder, the drive spindle, the chuck spindle and the piston all being hollow to permit a mandrel rod and blank to extend therethrough; and

bearing means connecting the piston with the chuck spindle and providing for rotary motion of the spindle with respect to the piston and for the piston and spindle to move axially in unison. 3. Blank feeding and turning apparatus for a high speed tube mill comprising:

an elongated bed;

a chuck slide and guide means supporting the chuck slide for reciprocating motion on the bed;

, a drive spindle rotatably mounted on the slide;

a chuck spindle;

means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison;

a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for turning and feeding of the blank;

a cylinder mounted on the chuck slide;

a piston mounted for reciprocating motion within the cylinder; and

bearing means connecting the piston with the chuck spindle and providing for rotary motion of the spindle with respect to the piston and for the piston and spindle to move axially in unison.

4. A construction in accordance with claim 3 wherein the chuck spindle and the piston are hollow to permit a mandrel rod and blank to extend therethrough and further including a chuck fixed on the bed and disposed to grip a mandrel rod extending through the chuck spindle and the piston.

5. In a high speed tube mill:

an elongated bed;

roller means to work a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller rolling back over the worked blank while releasing the same for turning and moving axially;

a mandrel to fit inside of and support a tubular blank for the working operation and a rod connected to the mandrel;

a chuck slide and guide means supporting the chuck I slide on the bed for reciprocating motion toward and away from the rollers;

a drive spindle rotatably mounted on the slide;

a chuck spindle;

means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison;

a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for turning and feeding of the blank;

blank turning means disposed on the chuck slide for movement therewith and connected with the drive spindle to rotate the spindles and thereby turn the chuck and blank; and

blank feeding means disposed on the bed and having mechanism connected with the chuck slide to move the slide along the bed and further having mechanism on the slide connected with the chuck spindle and permitting movement of the slide toward the rollers relative to the chuck spindle when the rollers are in the working stroke and which feeds the chuck spindle, the chuck and the blank toward the rollers during the return stroke.

6. In a high speed tube mill:

roller means adapted to reciprocate back and forth for working a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller means rolling back over the worked blank while releasing the same for turning and moving axially;

an elongated spindle mounted for rotation and for axial motion;

a chuck to grip a blank for the turning and axial feeding of the blank, the chuck being mounted on one end of the spindle;

a piston and bearing means mounting the piston on 14 the other end of said spindle, the bearing means providing for rotation of the spindle with respect to piston;

a fluid pressure cylinder containing said piston and moveable axially relative to the piston during the working stroke, the axial movement during the working stroke developing fluid pressure imposing an axial thrust on the piston which is operative during the return stroke to move the piston, spindle and chuck and thereby axially feed the blank into the rollers;

means to impose a torque on said spindle during the working stroke and during the return stroke and thereby cause the chuck to impose a torque on the blank, the effect of the torque on the blank during the return stroke being to turn the blank and the effect of the torque on the blank during the working stroke being accomodated by twist of the blank; and

means to determine the amount of turning and axial feed of the blank.

I i i 

1. In a high speed tube mill: roller means adapted to reciprocate back and forth to work a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller rolling back over the worked blank while releasing the same for turning and moving axially; a chuck to grip a blank to be worked; means supporting the chuck to turn and feed the blank after each working stroke including: a. mechanism to impose torque on the chuck during the time the rollers are in the working stroke and during the time the rollers are in the return stroke whereby the turning torque is operative for turning the blank simultaneously with the release of the blank by the rollers on the return stroke and the blank is turned during the return stroke for presenting to the rollers a section of the blank to be worked on the next working stroke, the effect of the torque on the blank during the working stroke being accommodated by twist of the blank; b. mechanism to impose an axial thrust on the chuck during the time the rollers are in the working stroke and during the time the rollers are in the return stroke whereby the axial thrust is operative for feeding the blank simultaneously with the release of the blank by tHe rollers on the return stroke and the blank is fed axially during the return stroke toward the rollers for presenting to the rollers a section of blank to be worked on the next working stroke, the effect of the thrust during the working stroke being accommodated by that the mechanism has a sliding connection and the turning of the blank being accommodated by that the mechanism has a rotary connection; and means to determine the amount of turning and axial feed of the blank.
 2. Blank feeding and turning apparatus for a high speed tube mill comprising: an elongated bed; a pair of spaced apart horizontally extending guide rods fixed on the top of the bed; a horizotally extending feed screw rotatably mounted on the bed between said guide rods; means connected with the bed to rotate the feed screw; a first horizontally extending platform; bushing means slidably mounting the platform on the guide rods for movement along the bed; a nut on the feed screw and connected with the platform, rotation of the screw in the nut moving the first platform along the bed; a second platform disposed above the first platform and moveable therewith; a drive motor mounted on the second platform; a hollow drive spindle rotatably mounted on the first platform; a drive connection between the drive spindle and the drive motor for rotating the spindle; a hollow chuck spindle; means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison; a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for the turning and feeding of the blank; a cylinder mounted on the first platform; a hollow piston mounted for reciprocating motion within the cylinder, the drive spindle, the chuck spindle and the piston all being hollow to permit a mandrel rod and blank to extend therethrough; and bearing means connecting the piston with the chuck spindle and providing for rotary motion of the spindle with respect to the piston and for the piston and spindle to move axially in unison.
 3. Blank feeding and turning apparatus for a high speed tube mill comprising: an elongated bed; a chuck slide and guide means supporting the chuck slide for reciprocating motion on the bed; a drive spindle rotatably mounted on the slide; a chuck spindle; means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison; a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for turning and feeding of the blank; a cylinder mounted on the chuck slide; a piston mounted for reciprocating motion within the cylinder; and bearing means connecting the piston with the chuck spindle and providing for rotary motion of the spindle with respect to the piston and for the piston and spindle to move axially in unison.
 4. A construction in accordance with claim 3 wherein the chuck spindle and the piston are hollow to permit a mandrel rod and blank to extend therethrough and further including a chuck fixed on the bed and disposed to grip a mandrel rod extending through the chuck spindle and the piston.
 5. In a high speed tube mill: an elongated bed; roller means to work a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller rolling back over the worked blank while releasing the same for turning and moving axially; a mandrel to fit inside of and support a tubular blank for the working operation and a rod connected to the mandrel; a chuck slide and guide means supporting the chuck slide on the bed for reciprocating motion toward and away from the rollers; a drive spindle rotatably mounted on the slide; a chuck spindle; means mounting the chuck spindle on the drive spindle and providing for relative axial movement of the spindles and for rotation of the spindles in unison; a chuck mounted on the chuck spindle to partake of axial and rotary motion thereof, the chuck being adapted to grip a tubular blank for turning and feeding of the blank; blank turning means disposed on the chuck slide for movement therewith and connected with the drive spindle to rotate the spindles and thereby turn the chuck and blank; and blank feeding means disposed on the bed and having mechanism connected with the chuck slide to move the slide along the bed and further having mechanism on the slide connected with the chuck spindle and permitting movement of the slide toward the rollers relative to the chuck spindle when the rollers are in the working stroke and which feeds the chuck spindle, the chuck and the blank toward the rollers during the return stroke.
 6. In a high speed tube mill: roller means adapted to reciprocate back and forth for working a tubular blank, the rollers having a working stroke and a return stroke, in the working stroke the rollers rolling over while engaged with the blank to work the same, the engagement gripping the blank and holding the same against turning and axial movement and in the return stroke the roller means rolling back over the worked blank while releasing the same for turning and moving axially; an elongated spindle mounted for rotation and for axial motion; a chuck to grip a blank for the turning and axial feeding of the blank, the chuck being mounted on one end of the spindle; a piston and bearing means mounting the piston on the other end of said spindle, the bearing means providing for rotation of the spindle with respect to piston; a fluid pressure cylinder containing said piston and moveable axially relative to the piston during the working stroke, the axial movement during the working stroke developing fluid pressure imposing an axial thrust on the piston which is operative during the return stroke to move the piston, spindle and chuck and thereby axially feed the blank into the rollers; means to impose a torque on said spindle during the working stroke and during the return stroke and thereby cause the chuck to impose a torque on the blank, the effect of the torque on the blank during the return stroke being to turn the blank and the effect of the torque on the blank during the working stroke being accomodated by twist of the blank; and means to determine the amount of turning and axial feed of the blank. 